1. Technical Field
The present disclosure relates to a baseline wander compensating method, in particular, to a baseline wander compensating method adapted for a baseline calibration module and Ethernet transceiver thereof.
2. Description of Related Art
In current electronic communication system, the trend is that digital data transmission becomes more important. Besides, as user's demand for high speed transmission increases, it further stimulates the development of Ethernet. However, during data transmission process, the shape of modulation wave received by an Ethernet transceiver is affected easily by channel distortion, which resulting in effect of killer packet and baseline wander. If the baseline wander cannot be compensated appropriately, error rate of the transceiver will be increased.
Please refer to FIG. 1 which is a block view of traditional Ethernet transceiver. The Ethernet transceiver 1 comprises an analog-digital converting unit 101, a compensation unit 102, an equalizer 103, a slicer 104, an adder 105 and an estimation unit 106. The compensation unit 102 is coupled to the analog-digital converting unit 101, and the equalizer 103 is coupled to the compensation unit 102, and the slicer 104 is coupled to the equalizer 103, and the adder 105 is coupled to the equalizer 103 and the slicer 104, and the estimation unit 106 is coupled to the adder 105 and the compensation unit 102.
In traditional Ethernet transceiver 1, an input signal IN_S is converted to a digital signal by the analog-digital converting unit 101. Next, the signal generated from the digital signal being processed by the equalizer 103 and the signal generated from the digital signal being processed by the equalizer 103 and the slicer 104 are added by the adder 105, and the added signal is transmitted to the estimation unit 106 for calculation of baseline wander. Then, the estimation unit 106 transmits the calculation result to the compensation unit 102 to execute compensation for the input signal IN_S.
According to the above mentioned, the traditional Ethernet transceiver 1 just executes compensation for input signal in digital domain. In detail, traditional Ethernet transceiver 1 utilizes a digital domain compensation algorithm with seven-bit or eight-bit high analog-digital converting resolution. Therefore, the traditional Ethernet transceiver 1 is limited to use regular loop bandwidth work mode but is hard to compensate for a normal packet and a killer packet simultaneously during signal process.